Turbo vs. blower debate w/in

[Swift_3800_F-Body]

is the stock drive shaft strong? in the 3.8's, i dont want that breakin anytime soon

[Tiago]

yes the stock driveshaft should be fine as long as its a one piece.

[mattsv6]

that is what i had been planning on from the beginning. i didnt want to say anything till the kits were in production, but the time has arise for it. we will be applying for a carb executive order number so the kits will be 50 state legal. so this is a very good thing to think abot when purchasing a kit. we might only be able to run the bosot around 4-6 pounds when we run the test, but that can be fixed easily one you install the kit.

[imported_admin]

<blockquote>quote:</font><hr>Originally posted by Arctc Wolf:
If u guys go for a EO number, go for a CARB EO number, and it'll be legal for all 50 states.<hr></blockquote>

Does not matter. It still has to pass the physical test with the sensor probes stuck in the exhaust pipes, which no modified F-Body with a turbo or blower could ever dream of doing.

My exhaust said it was "street legal" but I've received several noise violation tickets for it. Calling it "street legal" with some fancy CARB number is just a sales pitch and means nothing in the real world. :rolleyes:

[mattsv6]

if you get a carb eo number it will make a difference. the way they test the kit is to see how much more it makes the car polute the air. and if the driveability is bad for daily driving, they wont do it either. with a carb approved kit, it will be 100% street legal in its tested form and you will be able to pass on a stock car. from the people that i have talked to about getting the kit tested, it will be a 3 day process and it is very expensive. but i feel this is well worth it. and if your exhaust is carb approved and street legal, you should have no trouble beating a ticket in court. this is why all the 50 state legal catbacks come with certification and a sticker for underhood. and, if they didnt put a decibel meter to the exhaust it is an invalid ticket anyways ;)

[Arctc Wolf]

I'm not worried about noise, i can drive like grandma around cops. Having the carb # will make it easier for me 2 go get it smogged.

[mattsv6]

since this is a debate for turbo vs. blowers, there is one thing that i can point out! turbo's put out less emmisions in general then a blower. this is cause the turbo creates hea and force it through the catalytic converter. thus increasing the efficiency of the converter cause it needs heat too work properly. this is why they make you idle for 20 minutes before they emmisions test any vehicle.

[HAZ-Matt]

<blockquote>quote:</font><hr>Originally posted by mattsv6:
since this is a debate for turbo vs. blowers, there is one thing that i can point out! turbo's put out less emmisions in general then a blower. this is cause the turbo creates hea and force it through the catalytic converter. thus increasing the efficiency of the converter cause it needs heat too work properly. this is why they make you idle for 20 minutes before they emmisions test any vehicle.<hr></blockquote>

There is some talk of the government possibly changing the testing to a more instantaneous emissions test with a reduced, or possibly eliminated, warm up period.

In general, the hotter the catalytic converter, the better it is at reducing emissions. However, the flip side of the coin is that the hotter the operating temperature fo the catalytic converter, the shorter it's life.

[nocutt]

<blockquote>quote:</font><hr>Originally posted by mattsv6:
since this is a debate for turbo vs. blowers, there is one thing that i can point out! turbo's put out less emmisions in general then a blower. this is cause the turbo creates hea and force it through the catalytic converter. thus increasing the efficiency of the converter cause it needs heat too work properly. this is why they make you idle for 20 minutes before they emmisions test any vehicle.<hr></blockquote>


You are correct to an extent...but to add, the main problem with a turbo an emissions is the fact that the turbo pulls heat away from the cat. That is were turbo suck for cold start emissions...even after the cat lights-off, when the car sits the turbo does the same thing again...absorbs more heat...that is one of the reasons factory productions big turbo companies in the US use small turbos, turbos placed behind the CAT or very close to the front of the cat...either ways cold start emssions IS th eone problem associated with a turbo..
I still don't know how the import market get aftermarket bolt-on turbo kits an E.O. It most be who you know...

[mattsv6]

the way all the turbo tuner companies get their carb eo is cause they take all the measures and guidlines that is recommended by the testers. they run a "low boost" number and this in turbo bypasses the turbo housing almost completely. you are right that the turbo does act like a heat sink, but it also acts as a heating medium like a heat exchanger. once it is at operating temperature, it sends the heat to the cat in the exhaust and the piping. look at when a car is dynoed hard. the down pipe to the cat(s) glows red or more. this does translate alot of the heat to the cat shell. alot of these companies also dont run an intercooler for the testing cause this keeps the intake temps high, and higher intake = higher exhaust temps.

this is gonna be a learnign experience for myself and tiago because neither of us have gone through this process before. but we will quickly learn what is going to pass and what is not. they base everything compared to stock charecteristics. like driveability, exhaust emmisions, and most of all miles per gallon. they will be happy with a slightly higher nox reading if the car has excellent mileage. so we will see what happens when we do the testing.

[nocutt]

<blockquote>quote:</font><hr>Originally posted by mattsv6:
the way all the turbo tuner companies get their carb eo is cause they take all the measures and guidlines that is recommended by the testers. they run a "low boost" number and this in turbo bypasses the turbo housing almost completely. you are right that the turbo does act like a heat sink, but it also acts as a heating medium like a heat exchanger. once it is at operating temperature, it sends the heat to the cat in the exhaust and the piping. look at when a car is dynoed hard. the down pipe to the cat(s) glows red or more. this does translate alot of the heat to the cat shell. alot of these companies also dont run an intercooler for the testing cause this keeps the intake temps high, and higher intake = higher exhaust temps.

this is gonna be a learnign experience for myself and tiago because neither of us have gone through this process before. but we will quickly learn what is going to pass and what is not. they base everything compared to stock charecteristics. like driveability, exhaust emmisions, and most of all miles per gallon. they will be happy with a slightly higher nox reading if the car has excellent mileage. so we will see what happens when we do the testing.<hr></blockquote>

I agree but still cold start emissions is every aftermarket turbo tuners worst nightmare...especially here in cali. This is of course after a visual...nothwithstanding I think if the guidlines are met for either for the EPA and/or CARB a exemption order can be achieved.
I think the biggest issues I know of right now are:
* The original cat remain stock and in the stock position.
* Engine management functions (electronic) should remain unchanged.
* And the big one...Fuel System must function only under BOOST...
As far is the actual that is remain seen...

[ June 11, 2003: Message edited by: nocutt ]</p>

[mattsv6]

i totally agree with you about the cold start emmisions, but the epa and carb dont really use this as a basis for total judgement. the car is only cold for a little while anyways. but i do agree that it is a factor to them a little. all the things you mentioned with remain stock also. the fuel enrichment if boost referenced, so it wont do anything till you read + numbers.

[Bliggida]

<blockquote>quote:</font><hr>Originally posted by Arctc Wolf:
As usual, Turbo's are king of efficiency if they're set up right. roots blowers are so outa style cuz they heat up air too much. whipplecharger-style blowers are cool cuz of their root's-like attachment, but their twin-screw design kicks *** . centrifugal SC's are efficient, but still need a belt to turn them, drawing power from the hp they're making.

each one has their place. rotts blowers are good for low-boost, higher compression apps where a little more predictable low-end power is needed, centrifugal's are good for more top-end punch and reliable and easy to track boost increases. turbo's are for adjustability and high end power.

but now, turbo manufacturers such as Garrett are coming out w/ new technology and designs to make these even better. ceramic wheels to reduce weight and spool up quicker(but have a max boost capacity of around 17 psi because of wheel breakage), wheel design, ball-bearing center sections, housing aerodynamics, and housing materials. This allows the turbo's to make boost very quickly, and allows for even more efficient systems.

As long as a turbo system is designed and matched properly to the right engine, they will make a lot of power quickly, and efficiently.<hr></blockquote>

I have noticed through this thread and others that usually what is posted is either purely bias, not based on truth at all, or based only half-truths. I'm not calling out Artic Wolf here specifically. He simply made some statements I would like to touch on so that I don't leave anthing out, and forget later on in my post.

Having said that I will start by stating that off the bat I am biased towards a Supercharger, but that does not interfere with my knowledge or the facts I will explain.
While I am thinking about that idea - it also bugs me a little that people come here and say "A turbo is better because it flows better" without ever taking the time to back up themselves or explain why they think this is true. If you do not back yourself up with hard data it is merely opinion and/or bias.

*sigh*

Turbochargers and volumetric efficiency. Do Turbochargers flow well, yes they do, are they the best, no they are not. You cannot simply say turbo's are better because they flow better. There is much more to the equation than that. For example. At what point do they begin to flow better? You'd be hard pressed to find a turbocharger that flows the same amount of makes as much boost as a supercharger does at 2,000 RPM. So immediately you are faced with the prefacing idea that turbochargers only flow better than superchargers at high RPM. And is that statement true? Only in street driven force inducted motors. When you get into racing. Most blowers outflow the best Turbochargers. So it leads to the question "For what application is a turbocharger or supercharger better than the other" Well, for the most part I will agree that for sustained high RPM, a turbo will probably be your best choice, opposed to a supercharger. Where as off-idle acceleration, normal (read midrange) RPM range driving a supercharger is the better choice. But this is not an absolute. If turbochargers (in terms of all out power) were better they'd be used. But the idea of "no belt, no powerloss" is not neccesarily true. Look at off-shore power boats. These engines do nothing but rev near redline from start to finish of the race...but what do they use? Roots blowers. At high RPM? YES! Superchargers can and ARE built differently. You can just as easily make one more efficient for 8,000+ RPM high boost as you can make one a low end torque monster for the street.

Turbo's may not have a belt that robs power, but they have something a supercharger doesn't - HEAT. A turbocharger creates tremendous heat. Even intercooled. You are still faced with an air intake temperature far exceeding anything a roots blower will heat an incoming air charge. The supercharged engine gets fresh cold air, and this cooling process is further continued through carburetors as that air is forced over fuel, the fuel is then cooled and in racing conditions can actually get to freezing temperatures - this is why dragsters crew-chief will spray a thin coat of oil, PAM, or de-icer into the throttle blades before a run is made. Where as on a turbocharger your exhaust gasses at the downpipe will register around 1600 degrees, maybe more depending on application. Think about it. Is it strange to see a turbocharger begin to glow after hard use? When have you ever seen a supercharger do the same thing??? It doesn't happen. Roots blowers heat the incoming air charge more than centrifugal blowers do, that is certainly true. But it is still nothing in the face of what an turbocharged engine will see. heat kills horsepower.
To combat the heat you have an intercooler for a turbocharged engine, and and aftercooler for a supercharged engine. 'intercooling' a supercharger - specifically a roots blower is not a difficult task. I would venture to guess that lack of education sponsored this statement. *I am not meaning to nor intend to insult anyone*
The aftercooler of a roots blower is mated between the lower intake manifold and the blower casing itself. What's so hard about that? On a small or big block engine it is at the very top of the motor, depending on the lower intake manifold a inch to few inches above the deck heighth. And in most cases out of the engine bay. There is no easier engine part to work on than one that is outside of the engine bay!!!

Here was the statement made <blockquote>quote:</font><hr>rotts blowers are good for low-boost, higher compression apps where a little more predictable low-end power is needed, centrifugal's are good for more top-end punch and reliable and easy to track boost increases. turbo's are for adjustability and high end power.<hr></blockquote>
Roots blowers, again, are just as easily good for high-boost, low compression applications. Low end? They can be. But ultimately? No, they dominate the top end. Look at top fuel dragsters. They run close to 40 pounds of boost. I'd like to see a turbocharger anywhere near that boost range. A dragster from start to finish of the race doesn't go under 4 to 5,000 RPM. So where is the low-end you are talking about? They cross the traps in excess of 8,000 RPM making power the whole way. So you can't just automatically assume "Turbo=high, blower=low" and that's that. No sir-y-bob! Its the application you intend to be using that dictates what kind of blower or turbo you use and when it will be most efficient. Just as easily you could also build a turbocharger to produce high boost at LOW RPM.

I'm not out to kill the Turbo fans and make a turbo out to be some odd-ball that doesn't make power. No, do not get me wrong, PLEASE. A turbocharger is a great invention. But you have to look at it for what it is, just as much as you see what it can do. When you are talking about cars that these engines are going into. Turbocharging starts to make more sense.

What is it that a turbocharger does, no parasitic drag, does not produce worth-wild boost
until upper RPM. What application would this be best used in? For a turbo to be used to is optimum you'd need a car that can't start off the line well - does not make traction out of the hole, or in general do well with any significant amount of torque...I got it... a Front Wheel Drive car.

And look at where the turbocharger hype is at? Ricer's (lately) You get a car that doesn't launch well, and any amount of power down low will torque steer the car. So basically what you are telling me is that you only need power in the upper RPM range once you are able to gain traction. Sounds like a perfect setup...and it is. The FWD'r has physics going against them. It all comes down to weight transfer. There is only so much you can do to battle physics. Then you hit a brick wall or reality. So instead of boosting mega power low, mid and high rpm lets just put it in the range where the car makes traction and put the power down when traction is established. Bingo! Turby FWD, the best setup you can have. You start out with little to no boost when the tires are spinning through the first few gears, then as the traction is starting to be restored, boost starts to enter the equation and puts the power to the ground.

How does that help out in everyday driving though? Well, unless you are constantly pinging the engine off the RPM limiter, it doesn't. Unless you have a Variable Ramp rate tied into the timing...oh wait that's VTEC. Even still, in order to delve into the VTEC programming you must be above 5,000 RPM. Now, I will admit that I drive hard and fast on the street, more so than most people. But as hard as I am on the throttle, I don't think I reach high RPM enough to say its done so majority of the time, at that where my boost would be made if I had a turbocharger. So why have one on the street? Well if you have high boost capabilities, for one, if you stay out of the high RPM range your gas mileage will resemble a N/A car. Remaining low until you open the throttle and dial in boost from a controller. Also, in inclement weather, the ability to stay out of the boost will definately help keep you out of trouble.

There are some definate advantages of having a turbocharger, but being the fastest racer out there is not one of them. In any demonstration of acceleration turbo lag will slow you down compared to the same boost level of a supercharger.

But if we flip the tables and look not only at RWD but more closely at our specific platform - the fourth generation F-body. I have personally seen door-slammer 4th gen. F-bodies go 1.2 60-foot times or better. These vehicles have no problems what so ever at putting power to the ground off the line. So why would you want to put your boost in a place where it won't be accessible for a small percentage of your run when it could be applied from launch to shutdown as with a supercharger? Its a bit of a redundant question in terms of all out racing - you wouldn't. If you were competing in an acceleration test, and you have the ability to put power to the ground you would want boost from idle to redline. If our cars can handle torque, work to put more of it to the ground. But as I type see this I see the constant pattern forming in my own speech indicating maybe to some that a supercharger again is only good for low RPM and low end torque. But look at drag racing. Does any drag racer that is competetive (heads up racing) launch at idle? No. Do they launch anywhere near idle? No. Usually, with having an abundance of traction you are at the very minimum looking at a launch of at least midrange if not high RPM. If your supercharger is setup to produce boost at high RPM instead of low or midrange. When you drop that clutch, you will be blasted in the face with a very hard pull that will continue in each gear. With our engines, I doubt you'll ever go lower than 4,000 RPM during a drag race. And if your supercharger is setup for high RPM then when you get out onto the autocross tracks, and road racing tracks the supercharger will put power right where you will be racing.
The only time you want low-end boost is on a non performing street engine. Such as the Nissan Frontier. Not some roots blown muscle car. Most superchargers are actually geared to produce boost and the midrange level. Doesn't come in as hard (but still there) on the low end, pulls incredibly on the mid range, and continues on in the upper range (just not quite as strong). And when you look at what a typical "american engine" makes torque and horsepower you can see a definate power curve for an all around performance engine....
The torque comes in low for off-idle driving, around town putt-putt's. If you need to accelerate to get around a car and manuever through traffic the boost is helping you achieve that. And when you stomp on it, the high RPM horspower takes up the slack to pull you as you rev up. So basically there is no power band - it pulls from idle to red line smooth and powerfull everywhere.

Reminds me of another point - why would you supercharge or crate low boost on something that has no torque (FWD motors) these engine's don't make torque to begin with so why try to emphasize that when at best and boosted it will only be mediocre? Where as instead, these high end horsepower screamers will get a double dose if you turbocharge them.

But on an engine that does create both torque and horsepower, and has the chassis behind it to put that power down. The only thing better is to put more power down, following or slightly changing the power curve - supercharging.

And again that's not to say a RWD LS1 car is a bad example to be turbocharged. I've seen them running 8's in street legal trim. So when you look at the differences, advantages and disadvantages of each type, on the street its not so much of a difference in terms of total power output. But you get into racing, and the supercharger will win time after time.

For the street though, both have their good points and bad points, and to dictate which one will be better depends on the engine you are using, the chassis design, driver style, and total power you hope to achieve. There isn't one clear winner.

[hou-tex-six]

<blockquote>quote:</font><hr>Originally posted by Bliggida:

Roots blowers, again, are just as easily good for high-boost, low compression applications. Low end? They can be. But ultimately? No, they dominate the top end. Look at top fuel dragsters. They run close to 40 pounds of boost. I'd like to see a turbocharger anywhere near that boost range. A dragster from start to finish of the race doesn't go under 4 to 5,000 RPM. So where is the low-end you are talking about? They cross the traps in excess of 8,000 RPM making power the whole way. So you can't just automatically assume "Turbo=high, blower=low" and that's that. No sir-y-bob! Its the application you intend to be using that dictates what kind of blower or turbo you use and when it will be most efficient. Just as easily you could also build a turbocharger to produce high boost at LOW RPM.

I'm not out to kill the Turbo fans and make a turbo out to be some odd-ball that doesn't make power. No, do not get me wrong, PLEASE. A turbocharger is a great invention. But you have to look at it for what it is, just as much as you see what it can do. When you are talking about cars that these engines are going into. Turbocharging starts to make more sense.

What is it that a turbocharger does, no parasitic drag, does not produce worth-wild boost
until upper RPM. What application would this be best used in? For a turbo to be used to is optimum you'd need a car that can't start off the line well - does not make traction out of the hole, or in general do well with any significant amount of torque...I got it... a Front Wheel Drive car.

And look at where the turbocharger hype is at? Ricer's (lately) You get a car that doesn't launch well, and any amount of power down low will torque steer the car. So basically what you are telling me is that you only need power in the upper RPM range once you are able to gain traction. Sounds like a perfect setup...and it is. The FWD'r has physics going against them. It all comes down to weight transfer. There is only so much you can do to battle physics. Then you hit a brick wall or reality. So instead of boosting mega power low, mid and high rpm lets just put it in the range where the car makes traction and put the power down when traction is established. Bingo! Turby FWD, the best setup you can have. You start out with little to no boost when the tires are spinning through the first few gears, then as the traction is starting to be restored, boost starts to enter the equation and puts the power to the ground.

How does that help out in everyday driving though? Well, unless you are constantly pinging the engine off the RPM limiter, it doesn't. Unless you have a Variable Ramp rate tied into the timing...oh wait that's VTEC. Even still, in order to delve into the VTEC programming you must be above 5,000 RPM. Now, I will admit that I drive hard and fast on the street, more so than most people. But as hard as I am on the throttle, I don't think I reach high RPM enough to say its done so majority of the time, at that where my boost would be made if I had a turbocharger. So why have one on the street? Well if you have high boost capabilities, for one, if you stay out of the high RPM range your gas mileage will resemble a N/A car. Remaining low until you open the throttle and dial in boost from a controller. Also, in inclement weather, the ability to stay out of the boost will definately help keep you out of trouble.

There are some definate advantages of having a turbocharger, but being the fastest racer out there is not one of them. In any demonstration of acceleration turbo lag will slow you down compared to the same boost level of a supercharger.

But if we flip the tables and look not only at RWD but more closely at our specific platform - the fourth generation F-body. I have personally seen door-slammer 4th gen. F-bodies go 1.2 60-foot times or better. These vehicles have no problems what so ever at putting power to the ground off the line. So why would you want to put your boost in a place where it won't be accessible for a small percentage of your run when it could be applied from launch to shutdown as with a supercharger? Its a bit of a redundant question in terms of all out racing - you wouldn't. If you were competing in an acceleration test, and you have the ability to put power to the ground you would want boost from idle to redline. If our cars can handle torque, work to put more of it to the ground. But as I type see this I see the constant pattern forming in my own speech indicating maybe to some that a supercharger again is only good for low RPM and low end torque. But look at drag racing. Does any drag racer that is competetive (heads up racing) launch at idle? No. Do they launch anywhere near idle? No. Usually, with having an abundance of traction you are at the very minimum looking at a launch of at least midrange if not high RPM. If your supercharger is setup to produce boost at high RPM instead of low or midrange. When you drop that clutch, you will be blasted in the face with a very hard pull that will continue in each gear. With our engines, I doubt you'll ever go lower than 4,000 RPM during a drag race. And if your supercharger is setup for high RPM then when you get out onto the autocross tracks, and road racing tracks the supercharger will put power right where you will be racing.
The only time you want low-end boost is on a non performing street engine. Such as the Nissan Frontier. Not some roots blown muscle car. Most superchargers are actually geared to produce boost and the midrange level. Doesn't come in as hard (but still there) on the low end, pulls incredibly on the mid range, and continues on in the upper range (just not quite as strong). And when you look at what a typical "american engine" makes torque and horsepower you can see a definate power curve for an all around performance engine....
The torque comes in low for off-idle driving, around town putt-putt's. If you need to accelerate to get around a car and manuever through traffic the boost is helping you achieve that. And when you stomp on it, the high RPM horspower takes up the slack to pull you as you rev up. So basically there is no power band - it pulls from idle to red line smooth and powerfull everywhere.

Reminds me of another point - why would you supercharge or crate low boost on something that has no torque (FWD motors) these engine's don't make torque to begin with so why try to emphasize that when at best and boosted it will only be mediocre? Where as instead, these high end horsepower screamers will get a double dose if you turbocharge them.

But on an engine that does create both torque and horsepower, and has the chassis behind it to put that power down. The only thing better is to put more power down, following or slightly changing the power curve - supercharging.

And again that's not to say a RWD LS1 car is a bad example to be turbocharged. I've seen them running 8's in street legal trim. So when you look at the differences, advantages and disadvantages of each type, on the street its not so much of a difference in terms of total power output. But you get into racing, and the supercharger will win time after time.

For the street though, both have their good points and bad points, and to dictate which one will be better depends on the engine you are using, the chassis design, driver style, and total power you hope to achieve. There isn't one clear winner.<hr></blockquote>


you are an idiot


[img]tongue.gif[/img]

[Bliggida]

why?